Epitaxial quantum dots (QDs) have long been identified as promising charge spin qubits offering an efficient interface to quantum light and advanced semiconductor nanofabrication technologies. However, charge spin coherence is limited by interaction with the nanoscale ensemble of atomic nuclear spins, which is particularly problematic in strained self-assembled dots. Here, we use strain-free GaAs/AlGaAs QDs, demonstrating a fully functioning two-qubit quantum register using the nanoscale ensemble of arsenic quadrupolar nuclear spins as its hardware. Tailored radio-frequency pulses allow quantum state storage for up to 20 ms, and are used for few-microsecond single-qubit and two-qubit control gates with fidelities exceeding 97%. Combining long coherence and high-fidelity control with optical initialization and readout, we implement benchmark quantum computations such as Grover’s search and the Deutsch–Jozsa algorithm. Our results identify QD nuclei as a potential quantum information resource, which can complement charge spins and light particles in future QD circuits.

外延量子点 (QD) 长期以来一直被认为是有前途的电荷自旋量子比特，为量子光和先进的半导体纳米加工技术提供了有效的接口。然而，电荷自旋相干性受到与纳米级原子核自旋集合的相互作用的限制，这在应变自组装点中尤其成问题。在这里，我们使用无应变 GaAs/AlGaAs QD，展示了一个使用砷四极核自旋的纳米级集合作为其硬件的功能齐全的双量子位量子寄存器。定制的射频脉冲允许量子态存储长达 20 毫秒，并用于保真度超过 97% 的几微秒单量子位和双量子位控制门。将长相干和高保真控制与光学初始化和读出相结合，我们实现了基准量子计算，例如 Grover 搜索和 Deutsch-Jozsa 算法。我们的结果将 QD 原子核确定为一种潜在的量子信息资源，它可以补充未来 QD 电路中的电荷自旋和光粒子。